Due to its open nature, Maemo hasn't attracted yet high profile games to its platform. Nokia is working on ways to implement commercial software like games on Maemo, so it is probable it will happen in the future. In the summit it was mentioned that Maemo 6 (Harmattan) will have an open mode and a DRM mode; open mode being the device as we know it today and DRM mode the way more restricted apps can run. Maybe you could get an iPod Touch for the time being...?